Waterproofed fibrous material



ALBERT L. GLAPP, OF DENVER-S, IiIASSACHUSETTS, ASSIGNOR TO THE FLINTKQTE COMPANY, GE BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS,

WATER'PRUOFED FIBROUS MATERIAL.

.rTo Drawing.

To (ZZZ whom may concern:

Be it known that I, ALBERT L CLAPP, a citizen of the United States, residing at Denver's, in the county of Essex and State of Massachusetts, have invented new and useful improvements in Waterproofed Fibrous Materials, of which the following is a specification.

This invention has for its object, primarily, the waterproofing of fibrous materials, such as felt, paper and other sheet materal which is "formed in a web by papermaking machinery, but, in addition and perhaps of equal importance, the invention has for its object a method of mechanically precipitating or throwing down a pitch,

tar, bitumen, asphalt or other hydrocarbon which forms the disperse phase of an emulsion, of which water forms the continuous phase, so that the bitumen, asphalt or the like may be deposited upon the individual fibers of a fibrous material.

It is now known that bitumen, asphalt,

- making machine,

tar and other hydrocarbon oils and pitches, varying greatly in melting point, may be emulsified with water by the use ofan emulsifying agent, such as colloidal clay or other colloidal equivalent; and it is also known that such emulsions may be thinned or diiluted with water, and may be mixed with fibrous materials in a beating engine, and formed into a sheet or web in a papersuch as ordinarily cempldyed in the manufacture of, felt for roofing purposes. When a sheet is thus formed and is subjected to heat or pressure or both, the bituminous particlescoalesce and pro duce a final product which is to some extent iiot unlike a sheet of raw felt impregnated or saturated with pitch previously liquefied by heat.

l have discovered that it ispossible to throw down or precipitate the hydrocarbon or bituminousphase of the emulsion, and to accomplish this while the'emulsion is in admixture with the paper stock, so that the hydrocarbon or bitumen is deposited on the individual fibers, and also to cause the particles thereof to stick or adhereto the hers. Precipitating a ents, such as alum or other metal salts which are commonly used in precipitating rosin size or the like in sizing paper have no effect when used alone with an aqueous bitumen emulsion,

or bitumen Application filed October 25, 1520. Serial Kilo. 419,407.

but l have found that, if a solution of anima] protein is first mixed with the bitumen emulsion, and the preciptating agent is then added, a precipitate is formed which mechanically carries the particles of bitumen and serves as a coagulant therefor.

There are various animal proteins which may be employed. For example, i may use leather, hair, dried fish scraps and the like, I i

carries down with it the bitumen, all in a fiocculent mass. Apparently the gelatinous precipitate acts as an agglutinant or coagulant for the asphalt; but, at any rate, the solid matter is thrown down, leaving a clear liquid above it. If the reaction occurs when the solution and the emulsion (these terms being used principally to distinguish them) are in admixture with the fibrous paper stock, the gelatinous precipitate seems to act as a bond between the fibers and the particles of asphalt.

For exemplifying the production of a suitable animal protein; solution, I cite the following. Waste leather, containing little or no grease, and preferably sole leather, is placed in a vat or tank and suificlent water is added to submerge or cover it. The leather scraps'are permitted to soak long enough to wet them thoroughly,say for to minutes. Then to every 160 pounds of leather (dry weight) ll add about 12 to 15 pounds of caustic. soda (NaOH, 76% basis). The caustic alkali neutralizes the tannic acid and also softens the leather, being in excess of the amount required fpr neutralization of the acid, 'Aiter permitting the leather to soak fort/ea 15 to 30 minutes, the whole mass is lieate and boiled until a liquor is produced which is clear, Such liquor consists of a solution of animal protein, which is of a colloidal nature and which in this case is of a brownish to reddish color. As I have before stated, various other imal proteins may be sub and the paste is added tomolten asphalt and so mixed therewith as to produce an emulsion in which water constitutes the continuous phase andthe clay-asphalt particles the disperse phase. Such an emulsion is nonsticky and may be further thinned and diluted with water. y

The animal-protein solution "having been prepared, I proceed as follows. I place in a beating engine the desired fibrous materials, such as rags, wood pulp (ground or chemical) sawdust, etc., according to the required specifications of the ultimate product, with sufficient water to ensure the circulation of the mass in the beater tub. This fibrous stock is then beaten and disintegrated to the desired degree of fineness. Then the knives are lifted from the bed plate and the asphalt emulsion is added, the operation of the beater being continued until a homogeneous mixture is secured. The proportion of the asphalt emulsion is varied according to the amount of asphalt which the finishedsheet should contain, but, for example, it may be added in the proportion of 300 pounds of asphalt and clay (dry weight) to 1,000 pounds of paper stock (dry weight) in the beater.

The animal-protein solution may be added to the paper stock either at the time the raw materials are first introduced into the beater, or when the asphalt emulsion is added, or after the addition of the emulsion, but I prefer to add it coincidently with the addition of the emulsion, so that no additional time is required for its further homogeneous admixture with the paper stock and the emulsion. For 300 pounds of clay and asphalt in the emulsion, sufficient protein solution should be added to represent 100 pounds '(dry weight) of leather or other animal protein. and the solution are thoroughly mixed before being supplied to the beater. The protein liquor acts to carry the asphalt in uniform suspension throughout the fibrous material.

I now add a precipitant, preferably alum (14% to 16% anhydrous aluminium "sulphate) in the proportion of 25 to 30 pounds to 100 poundsv of the animal protein (dry weight), and thoroughly incorporate it in the mass in the beater. This is sufficient to i In the example herein given,

Preferably the emulsion nsaaaoo The mass of pulp is now ready to be the fibers or causing it to adsheeted, and this is accomplished by the use of any suitable form of paper-making Inachinery such as is employed in the manufacture of raw paper felt, boxhoard or the like. The water is removed from the stock according to the usual methods, and the sheet or web is heated and dried. The final product is more satisfactorily Waterproofed than has heretofore been possible, when the asphalt emulsion was incorporated in the fibrous material without precipitation. The gelatinous aluminium hydrate acts not only as an agglutinating agent for the asphalt, to disturb or break down the asphalt emulsion, but it also acts, itself, as a waterproofing agent.

Some difiiculty has heretofore been experienced in sheeting pulp having an asphalt emulsion incorporated therein due to the balling of the asphalt particles, as the asphalt is thereby prevented from being uniformly distributed throughout the sheet. When this occurs, the balls adhere more or less to the felts or blankets of the paper making machine, with the result that the felts or blankets must be frequently cleaned.

By practicing my process as herein described. I obviate largely, if not entirely, these difficulties. The protein solution car rise the asphalt particles in suspension and aids in bringing about a more perfect homogeneity in the mixture of pulp and asphalt and prevents the asphalt from balling or agglomerating or coalescing in large particles. While the precipitating agent, he metal salt-is inert in reference to asphalt, and does not chemically act thereon as a precipitating agent, it does react with the protein solution, the precipitate acting to carry with it the asphalt particles, thereby disturbing or breaking down the emulsion.

the sodium sulphite, resulting from the reaction of the alkaline protein solution withaluminium sulphate, being soluble in water, is removed by the wash water.

What I claim is: t

1. The herein described process of breaking down an aqueous bituminous emulsion in which bitumen constitutes the disperse phase which comprises adding thereto an alkaline protein solution, and a precipitating agent capable of reaction with said solution to form a precipitate by which the bituminous particles are thrown down;

aluminium hydrate bonding 1,5es,1oo

2. The herein described process of breaking down an aqueous bituminous emulsion in which bitumen constitutes the disperse phase, which comprises adding thereto an alkaline animal-protein solution and a metal salt capable of reacting with said solution to produce a gelatinous hydrate.

8. The herein described process of break-- ing down an aqueous bituminous emulsion in which bitumen constitutes the disperse phase, which comprises adding thereto an alkaline animal-protein solution and aluminium sulphate whereby a gelatinous aluminium hydrate is precipitated, which acts to throw down the bitumen from the emulsion.

4;. The herein described process of breaking down an aqueous bituminous emulsion in which bitumen constitutes the disperse phase, which comprises adding thereto an aqueous solution of leather and caustic alkali, and finally a metal salt capable of reacting with said solution to precipitate a gelatinous metal hydrate, which carries with it the bituminous particles.

.5. The herein described process, which --icomprises mixing fibrous material, an aqueous bituminous emulsion, and an 'akaline protein solution, and then adding a precipitant to form a water-insoluble precipitate from said solution, by which the emulsion is broken down and the bituminous particles deposited on the fibers.

6. The herein described process, which comprises mixing fibrous material, an aqueous bituminous emulsion, and an alkaline protein solution, and'then adding a precip itant to form a water-insoluble precipitate from said solution, by which the emulsion is broken down and the bituminous particles deposited on the fibers, and finally forming the fibers into a web or sheet.

7. The herein described process, which comprises mixing fibrous material, an aqueous bituminous emulsion, and an alkaline solution of animal protein, and then precipitating a gelatinous hydrate from said solution, whereby the bituminous particles are deposited on the fibers.

8. The herein described process, which comprises mixing fibrous'material, an a neous bituminous emulsion, and an alka ine leather solution, then adding a metal salt capable of reacting with such solution to 'precipitate a gelatinous metal hydrate,

whereby said emulsion is broken down and the particles of bitumen are deposited on the fibers.

9. The herein described process, which comprises mixing fibrous material, an equeous bituminous emulsion, and an alkaline leather solution, then adding a metal salt capable of reacting with such solution to precipitate a gelatinous metal hydrate, whereby said emulsion is broken down and the particles of bitumen are deposited on the fibers, and finally sheeting said fibrous mass.

10. A process comprising mixing fibrous material and an aqueous bituminous emul sion in which the bitumen constitutes the disperse phase, and separately adding reacting ingredients to such mixture to form a precipitating agent by which the bitumen is deposited on the fibers. 1

11. A process, comprising mixing fibrous material, an aqueous bituminous emulsion, and a soluble solution of a body capable of producing a gelatinous precipitate, and then adding a precipitating agent, whereby a gelatinous precipitate is formed and particles of bitumen are deposited on the fibers.

In testimony whereof I have afixed my signature.

ALBERT L. CLAPP. 

